Method of forming metal zipper teeth and forming device thereof

ABSTRACT

A method for forming metal zipper teeth includes following steps: a step of forming embryonic teeth, a material wire being stamped and cut by way of an upper blank mold and a lower blank mold to form embryonic teeth detaching from the material wire; a step of corner cutting, redundant material at two outer ends on the open end of each of the embryonic teeth being removed by way of an upper corner cutting mold and a lower corner cutting mold so that almost finished zipper teeth can be obtained; and a step of forming, each of the almost finished zipper teeth being worked to have a tooth recess at the top thereof and a tooth jut at the bottom thereof by way of an upper forming mold and a lower forming mold and finished zipper teeth being complete.

FIELD OF THE INVENTION

The present invention relates to technique of metal zipper andparticularly to a method of forming metal zipper teeth and a device tocarry out the method.

BACKGROUND OF THE INVENTION

Metal zippers are frequently seen in our daily lives and in fact, themetal zippers are developed much earlier than the nylon zippers andfiber reinforced plastic zippers. Usually, the metal zippers can bedivided into aluminum zippers and copper zippers.

The principle of a metal zipper, as shown in FIG. 1, basically has twocloth strips a and a cord b is provided at the cloth strips respectivelyto face to each other. The respective cord b is clipped with a pluralityof equidistantly arranged zipper teeth c and a gap between two adjacentteeth of one of the cords is the height of each zipper tooth c2 of theother cord so that the zipper teeth at the cords can be joined firmly toeach other once the a zipper head is pulled upward. Therefore, eachzipper tooth (c1, c2) has a tooth jut d extending in a direction and thebackside of the zipper tooth corresponding to the tooth jut d is a toothrecess e. As a result, when the zipper teeth is in a state of beingjoined to each other, the tooth jut d at least at the front end thereofis received in the tooth recess e to constitute engagement as shown inFIG. 1.

Referring to FIGS. 2 and 3, in order to allow the zipper teeth (c1, c2)to clip the cord b of the cloth strip a, an upper mold set f and a lowermold set g are provided to form the zipper teeth c with stamping. Thedash lines at left side of FIG. 2 indicate the metal wire w, whichusually is aluminum or copper, and the metal wire is fed with the frontend thereof entering the lower mold g and the upper mold f and the lowermold g provide tooth jut mold (h1, h2) corresponding to each other. Oncethe operation of stamping is performed, the metal wire is worked withthe upper and lower mold sets f, g joining to each other such that eachof the zipper teeth c can be formed the tooth jut d at the upper partthereof and the tooth recess e at the lower part thereof. Besides, theupper and lower mold sets f, g provides two cutting molds (k1, k2)extending inward for forming a neck part 1 during stamping and the neckpart 1 can be worked by the forming molds (m1, m2) to form independentzipper teeth c. Meanwhile, the cord b of the cloth a passes through theopenings of the zipper teeth c and the cord c is clipped by the zipperteeth c by way of left and right molds joining to each other. Theoperation is repeated to carry out the work of planting teeth on thecord b. It is known that the method and the device have been used foryears and the entire process has been developed as automatic production.Although the convention way can reach the purpose of teeth planting, thedeficiency is one time forming such that there are cutting clear scarson the zipper teeth resulting from stamping such as lateral cuttingnotches of the zipper teeth at the neck 1 and the cord b and even atintersections of lines. After the zipper teeth being formed, there is nochange to trim or treat the surface of each zipper tooth so that it iscoarse without a sense of good quality and sharp corners on the zipperteeth being not chamfered results in being not smooth zipper teethengagement during the zipper being pulled up.

SUMMARY OF THE INVENTION

The crux of the present invention is to provide a method for formingmetal zipper teeth includes following steps: a step of forming embryonicteeth, a material wire being stamped and cut by way of an upper blankmold and a lower blank mold to form embryonic teeth detaching from thematerial wire; a step of corner cutting, redundant material at two outerends on the open end of each of the embryonic teeth being removed by wayof an upper corner cutting mold and a lower corner cutting mold so thata most finished zipper teeth can be obtained; and a step of forming,each of the almost finished zipper teeth being worked to have a toothrecess at the top thereof and a tooth jut at the bottom thereof by wayof an upper forming mold and a lower forming mold and finished zipperteeth being complete.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reference to thefollowing description and accompanying drawings, in which:

FIG. 1 is a plan view of a metal zipper illustrating the constructionthereof;

FIG. 2 is a perspective view illustrating teeth of the metal zipperbeing planted;

FIG. 3 is a plan view illustrating relation between the zipper teethforming and the core; and

FIG. 4 is a perspective view illustrating a forming device of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 4, a method of forming metal zipper teeth of thepresent invention can be explained in company with a forming device forthe metal zipper teeth. The forming device includes a blank mold 1, acorner cutting mold 2, one or more forming molds 3, a rotary mold seat 4and/or a core holding device 5.

Wherein, the blank mold 1 has an upper mold part 11 and a lower moldpart 12 for the zipper teeth being formed with an approximate shaperespectively and being separated from the original material wire A.Thus, once the material wire A enters the blank mold 1, the materialwire A is stamped and cut and embryonic teeth B of the zipper can beobtained. The formed zipper teeth are delivered with the rotary moldseat 4.

The corner cutting mold 2 is composed of an upper cutting mold 21 and alower cutting mold 22 (not shown) disposed on the rotary mold seat 4 forcutting residue material X at the outer end section on the open end of aholding core b to constitute unfinished and ready to be formed zipperteeth C. The ready to be formed zipper teeth C are provided with a flatshape respectively without the preceding tooth jut d and tooth recess.

One or more of the forming molds 3 are provided in the forming deviceand each of the forming molds 3 includes an upper forming mold 31 and alower forming mold 41, which is attached to the rotary mold base 4. Onlystamping is processed and no cutting is engaged at the stage of theforming molds. Each of the zipper teeth is formed with the tooth recessc at the upper part thereof and the tooth jut d at the bottom partthereof as shown in FIG. 4. There are four steps at the forming stages,i.e., upper forming molds 31, 31-1, 31-2, 31-3 and lower forming molds41, 41-1, 41-2, 41-3 but, it still depends on the actual need.Basically, more steps get involved in the mold tool stamping process andsofter product can be obtained so that the preceding scars, sharpcorners, burrs and etc. can be eliminated.

The rotary mold base 4 provides one or more lower forming molds 41 forthe lower cutting corner molds 22 so that the lower forming molds 41 canbe disposed in a way of equiangular position along the outer edge of themold base to rotate a preset angular motion by way of conventionalautomatic control for being capable of obtaining zipper teeth D4available for being held to the cord b.

The cord holding device 5 is conventional device for and can be providedat formed zipper teeth D and the cord b can be held to the formed zipperteeth D while the cord b moves upward to pass through the cord holdingdevice 5 so as to form a zipper strip with a lateral side thereof havingzipper teeth. by way of automatic control with programming.

It is appreciated that the method of forming metal zipper teeth withforming device thereof has the following advantages:

1. The traditional material wire can be utilized in the method anddevice of the present invention without changing material source andhabit using material.

2. The tooth jut and the tooth recess become delicate via multipleforming steps being joined to the mold design and it is helpful toenhance the quality thereof.

3. The outer walls of the zipper teeth become more smooth after multipleforming steps being performed so that it is helpful for the zipper beingopened and shut easily with gentle sense of touch.

4. The tooth recess faces upward and it is different from theconventional way of forming so that it is different from successivedesign and utilization of the tooth recess.

5. The forming device is independent of the device for detaching fromthe material wire so that it is flexible to install, maintenance andrepair.

While the invention has been described with reference to the a preferredembodiment thereof, it is to be understood that modifications orvariations may be easily made without departing from the spirit of thisinvention, which is defined by the appended claims.

1. A forming device of metal zipper teeth, comprising: a blank mold,providing an upper blank mold and a corresponding lower blank forstamping and cutting material wire as embryonic teeth with approximateshape of the zipper teeth; a corner cutting mold, providing an uppercorner cutting mold and a lower corner cutting mold for removing twofront ends of an open end of each of the embryonic teeth; a formingmold, providing at least an upper forming mold for stamping a toothrecess in each of the embryonic teeth and a lower forming moldcorresponding to the upper forming mold for forming the tooth recesswith the upper forming mold; and a rotary mold base, being disposed withthe lower corner cutting mold and the lower forming mold and beingcapable of turning a preset angular displacement.
 2. The forming deviceof metal zipper teeth as defined in claim 1, further comprises a cordholding device for formed zipper teeth being joined to a cloth cord. 3.The forming device of metal zipper teeth as defined in claim 1, whereinthe respective lower forming mold is disposed at an equiangular positionon the outer edge of the rotary mold base.
 4. The forming device ofmetal zipper teeth as defined in claim 1, wherein the lower cornercutting mold is disposed on the rotary mold base.
 5. A method forforming metal zipper teeth, comprising following steps: a step offorming embryonic teeth, a material wire being stamped and cut by way ofan upper blank mold and a lower blank mold to form embryonic teethdetaching from the material wire; a step of corner cutting, redundantmaterial at two outer ends on the open end of each of the embryonicteeth being removed by way of an upper corner cutting mold and a lowercorner cutting mold so that almost finished zipper teeth can beobtained; and a step of forming, each of the almost finished zipperteeth being worked to have a tooth recess at the top thereof and a toothjut at the bottom thereof by way of an upper forming mold and a lowerforming mold and finished zipper teeth being complete.
 6. The method forforming metal zipper teeth as defined in claim 5, further comprises acord holding step to allow the finished zipper teeth at the respectiveopen end thereof holding a cloth cord and form a zipper strip.
 7. Themethod for forming metal zipper teeth as defined in claim 5, wherein thestep of forming can be operated a plurality of times by way of the lowerforming mold being disposed on a rotary mold base with an equiangularposition to turn a preset angular displacement and the forming molds canbe corresponding to each other and the zipper teeth are formedsequentially.
 8. The method for forming metal zipper teeth as defined inclaim 5, wherein the material wire is made of aluminum or copper.